1. Field of the Invention
This invention relates generally to voice messaging systems. More particularly, it relates to a telephone answering device capable of receiving and storing separately secured voice messages from a calling party and of allowing a particular user or other designated party to access the separately secured voice messages.
2. Background of Related Art
Voice messaging systems in general, and telephone answering devices (i.e., answering machines) in particular, are useful devices for the home or office. For instance, a conventional telephone answering device operates on a single telephone line and answers an incoming call to an unused (i.e., on-hook) telephone after a desired number of rings. In response to an incoming call, a telephone answering device causes a telephone line to enter an off-hook condition, then plays an outgoing greeting message to the calling party. After the outgoing greeting message, the calling party typically may leave a voice message on the telephone answering device. At a later time, the voice message is replayed by the user, either local to the telephone answering device or via remote connection from another telephone.
FIG. 7 illustrates a conventional telephone answering device capable of answering an incoming call on a telephone line. In FIG. 7, a telephone answering device 11 is connected to a telephone company central office 13 via a telephone line 15. A telephone line interface (TLI) 17 in the telephone answering device 11 provides the conventional isolation, DC and AC impedance as required by telephone company standards. The telephone line interface 17 also provides a ring detect signal to a controller 19. The controller 19 may be any suitable processor, e.g., microprocessor, microcontroller, or digital signal processor (DSP). The ring detect signal indicates to the controller 19 the ringing of an incoming telephone call on the telephone line 15.
After a desired number of ring signals, the telephone answering device 11 causes the telephone line interface 17 to place the telephone line in an off-hook state, and instructs a voice recorder/playback audio module 21 to play an outgoing greeting message over the telephone line 15 to the calling party. Upon completion of the outgoing greeting message, the calling party may leave a voice message in voice message memory 23 under the control of the controller 19. A keypad 25 allows the user to select various modes of operation, including the playback of voice messages.
The conventional telephone answering device 11 illustrated in FIG. 7 further includes a call related information (e.g., Calling Identity Delivery (Caller ID)) detector/receiver 27 to detect and receive from a central office call related information, e.g., the telephone number and/or household name of a calling party. The call related information may be displayed on a display 29.
By using Caller ID or other call related information data service, the user of the conventional telephone answering device 11 can determine the name and/or telephone number of the calling party either before the incoming call is answered, and/or when an associated voice message is played back. Basic call related information services such as Caller ID typically transmit call related information from the local telephone company to the called party while the called party's phone is in a hung-up or on-hook state, e.g., between the first and second rings.
Oftentimes, it is important or necessary for the calling party to leave a private voice message for a particular user of a voice messaging system or other designated party. Conventional voice messaging systems provide separate voice mailboxes, typically each at a different extension. The calling party inputs a particular extension number relating to a particular voice mailbox, and is given the opportunity to record a voice message for storage in the designated voice mailbox.
However, in conventional voice messaging systems, all messages left in any one particular voice mailbox are accessible by all users of that particular voice mailbox. Unfortunately, a conventional multi-user voice messaging system does not prevent an otherwise unauthorized user to playback and listen to any particular voice message in any one voice mailbox.
Accordingly, there exists a need for a telephone answering device which prevents unauthorized playback of private voice messages.